Postoperative drainage of blood and other fluids that tend to collect at a surgical site is necessary to promote proper healing and prevent harm to surrounding tissues and organs. Drainage at the surgical site is particularly important in procedures carried out in the chest cavity, such as cardiac or spine procedures. Without proper drainage, the pooling of blood and fluid in the chest cavity can prevent the lungs from fully expanding to allow normal breathing, which could endanger a patient's life.
Commonly used devices for managing the collection of blood and fluid from a surgical site in a postoperative environment are disposable, relatively simple and lack automated controls. Examples of commonly used devices include the Pleura Vac S-1100 made by Genzyme Corporation of Fall River, Mass. and the Atrium Oasis # AW002714-003B available from Atrium Medical Corporation of Hudson, N.H. Such devices comprise a light weight portable container having a serpentine fluid pathway into which blood and fluid from the patient is aspirated. The devices rely on an external source of vacuum to aspirate the fluid, such as connection to a wall suction port accessing a facility wide vacuum system, which is available in many hospitals. At the end of the serpentine fluid pathway is provided a column of water, sealing the patient side of the pathway from the vacuum source side of the pathway. The column of water serves as a seal to prevent reversal of flow back to the patient if suction is discontinued.
The process of postoperative surgical site drainage can also provide an indication to the health care provider of the status of surgical wound condition. Normal healing of the surgical wound is indicated by a steady decrease over time in the amount of blood and fluid collected from the surgical site. An unexpected cessation of fluid collection may be an indication of a blockage in the drain tube created by blood clotting. Such a blockage requires attention by the care provider to reestablish drainage flow. Continuing high amounts of fluid collection or a sudden increase in fluid collection after a period of reduced amounts of collected fluid may indicate bleeding at the surgical site that requires attention of the care provider.
Because the known manual collection devices mentioned above lack automated controls, the progress of fluid collection must be monitored actively by the care provider. To observe the indications of wound status mentioned above, the care provider must return to the collection device at regular time intervals and visually observe the amount of fluid that has been collected since the last observation. Such labor-intensive monitoring is wasteful of the care provider's time and endangers the patient because problems that arise between observation visits will not be noticed until the next regularly scheduled status check is made by the care provider.
It would be desirable to provide a postoperative fluid drain system that continuously monitors the drainage process and automatically alerts care providers when drainage flow characteristics indicate a potential problem with the process. It is an object of the present invention to provide such a system.